[PATCH vhost 4/7] vdpa/mlx5: Introduce per vq and device resume

Dragos Tatulea
2023-12-01T10:50:08Z

Implement vdpa vq and device resume if capability detected. Add support
for suspend -> ready state change.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
---
drivers/vdpa/mlx5/net/mlx5_vnet.c | 67 +++++++++++++++++++++++++++----
1 file changed, 60 insertions(+), 7 deletions(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index d06285e46fe2..68e534cb57e2 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1170,7 +1170,12 @@ static int query_virtqueue(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueu
return err;
}

-static bool is_valid_state_change(int oldstate, int newstate)
+static bool is_resumable(struct mlx5_vdpa_net *ndev)
+{
+ return ndev->mvdev.vdev.config->resume;
+}
+
+static bool is_valid_state_change(int oldstate, int newstate, bool resumable)
{
switch (oldstate) {
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_INIT:
@@ -1178,6 +1183,7 @@ static bool is_valid_state_change(int oldstate, int newstate)
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY:
return newstate == MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND;
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND:
+ return resumable ? newstate == MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY : false;
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_ERR:
default:
return false;
@@ -1200,6 +1206,7 @@ static int modify_virtqueue(struct mlx5_vdpa_net *ndev,
{
int inlen = MLX5_ST_SZ_BYTES(modify_virtio_net_q_in);
u32 out[MLX5_ST_SZ_DW(modify_virtio_net_q_out)] = {};
+ bool state_change = false;
void *obj_context;
void *cmd_hdr;
void *in;
@@ -1211,9 +1218,6 @@ static int modify_virtqueue(struct mlx5_vdpa_net *ndev,
if (!modifiable_virtqueue_fields(mvq))
return -EINVAL;

- if (!is_valid_state_change(mvq->fw_state, state))
- return -EINVAL;
-
in = kzalloc(inlen, GFP_KERNEL);
if (!in)
return -ENOMEM;
@@ -1226,17 +1230,29 @@ static int modify_virtqueue(struct mlx5_vdpa_net *ndev,
MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, uid, ndev->mvdev.res.uid);

obj_context = MLX5_ADDR_OF(modify_virtio_net_q_in, in, obj_context);
- if (mvq->modified_fields & MLX5_VIRTQ_MODIFY_MASK_STATE)
+
+ if (mvq->modified_fields & MLX5_VIRTQ_MODIFY_MASK_STATE) {
+ if (!is_valid_state_change(mvq->fw_state, state, is_resumable(ndev))) {
+ err = -EINVAL;
+ goto done;
+ }
+
MLX5_SET(virtio_net_q_object, obj_context, state, state);
+ state_change = true;
+ }

MLX5_SET64(virtio_net_q_object, obj_context, modify_field_select, mvq->modified_fields);
err = mlx5_cmd_exec(ndev->mvdev.mdev, in, inlen, out, sizeof(out));
- kfree(in);
- if (!err)
+ if (err)
+ goto done;
+
+ if (state_change)
mvq->fw_state = state;

mvq->modified_fields = 0;

+done:
+ kfree(in);
return err;
}

@@ -1430,6 +1446,24 @@ static void suspend_vqs(struct mlx5_vdpa_net *ndev)
suspend_vq(ndev, &ndev->vqs[i]);
}

+static void resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
+{
+ if (!mvq->initialized || !is_resumable(ndev))
+ return;
+
+ if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND)
+ return;
+
+ if (modify_virtqueue_state(ndev, mvq, MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY))
+ mlx5_vdpa_warn(&ndev->mvdev, "modify to resume failed\n");
+}
+
+static void resume_vqs(struct mlx5_vdpa_net *ndev)
+{
+ for (int i = 0; i < ndev->mvdev.max_vqs; i++)
+ resume_vq(ndev, &ndev->vqs[i]);
+}
+
static void teardown_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
{
if (!mvq->initialized)
@@ -3256,6 +3290,21 @@ static int mlx5_vdpa_suspend(struct vdpa_device *vdev)
return 0;
}

+static int mlx5_vdpa_resume(struct vdpa_device *vdev)
+{
+ struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
+ struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
+
+ mlx5_vdpa_info(mvdev, "resuming device\n");
+
+ down_write(&ndev->reslock);
+ mvdev->suspended = false;
+ resume_vqs(ndev);
+ register_link_notifier(ndev);
+ up_write(&ndev->reslock);
+ return 0;
+}
+
static int mlx5_set_group_asid(struct vdpa_device *vdev, u32 group,
unsigned int asid)
{
@@ -3312,6 +3361,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = {
.get_vq_dma_dev = mlx5_get_vq_dma_dev,
.free = mlx5_vdpa_free,
.suspend = mlx5_vdpa_suspend,
+ .resume = mlx5_vdpa_resume, /* Op disabled if not supported. */
};

static int query_mtu(struct mlx5_core_dev *mdev, u16 *mtu)
@@ -3683,6 +3733,9 @@ static int mlx5v_probe(struct auxiliary_device *adev,
if (!MLX5_CAP_DEV_VDPA_EMULATION(mdev, desc_group_mkey_supported))
mgtdev->vdpa_ops.get_vq_desc_group = NULL;

+ if (!MLX5_CAP_DEV_VDPA_EMULATION(mdev, freeze_to_rdy_supported))
+ mgtdev->vdpa_ops.resume = NULL;
+
err = vdpa_mgmtdev_register(&mgtdev->mgtdev);
if (err)
goto reg_err;
--
2.42.0